Air draft Mainship 40

[philrains]

We have a 2008 Mainship 40. Does anyone know the air draft when the radar mast is down?

We will be transiting the Erie Canal this spring and I want to know if we can clear the fixed bridges on the Western leg from Palymya to Tonawanda.

If I have to, I will even remove the rail at the front of the fly bridge.

 

[RT Firefly]

Greetings,
Welcome aboard.

 

[ronlord]

You will be fine. We have a Mainship 350, air draft with our mast down and bridge enclosure up is exactly 15' Your enclosure may be higher if you have one. We have cruised the entire length of the canal twice over with no issues. Lowest bridge is about 15.5', and that is at high water. Most of them even on the western end are about 17' PM me if you need any information on the canal.

-Ron

 

[philrains]

Ron
Thanks much. I'll make sure to put your address in my mail box. May/June is still a dream here in Chicago, so planning is my only way to keep sane
Phil

 

[rwidman]

I would like to find the actual air draft on my boat with the bimini up, the bimini folded, and the bimini laid down (a modification I made by replacing some screws with removable pins.

I'm thinking I have to place a board on the highest part, level it, then measure from the end ot the board to the water.

Is there a better way?

 

[eseyoung]

I just used a tape measure. Measured from waterline to deck, then deck to hard top then hardtop to highest top of my radar arch.

add up the measurements and you will be right on.

 

[rwidman]

I just used a tape measure. Measured from waterline to deck, then deck to hard top then hardtop to highest top of my radar arch.

add up the measurements and you will be right on.

Thanks. That's easier and should be close enough for what I need. It's going to change a bit with loading anyway.

 

[psneeld]

While knowing your actual air draft is nice....so many bridges are charted incorrectly (at least along the Eastern Seaboard) that plus or minus a few feet certainly is acceptable as you never really knw till you get your highest point almost to the point of no return.

Books usually teach that bridge clearance is to the navigational height yet I have found some bridges that measure the center...others use terms like "low steel" (sounds like the country engineer isn't a boater)....many just are incorrect to the tune of several feet and some are discussed in great length in Active Captain and other sources.

Some bridges have optical clearance sighting systems and other bridges have the "we can't tell you anything" policy.

I certainly hope some fixed bridges that limit navigation through a major waterway are pretty accurately measured...like the Erie Canal Route...but I'm amazed that in today's world of laser measurement and overreaction when boats bump bridges that the whole world of bridges isn't a little clearer to the mariner.

 

[rwidman]

I have to go under a pair of bridges to go anywhere. One is charted at 14', the other at 16'. Since they are the two sides of the same road, you have to clear both so it's odd that they would list different heights. In effect the clearance is 14'. There are no boards and the operator will only tell you the listed clearance, not the actual. I have to guess if I need to lay the bimini top down.

That said, any bridge has a fixed height with respect to the surrounding land or the bottom of the water but the water level can vary even in non tidal situations.

It would be nice though, if all bridges had boards listing the clearance and if all were listed in a standard way.

It's not going to happen anytime soon so I guess there's no point in worrying about it.

 

[ronlord]

Ron
Thanks much. I'll make sure to put your address in my mail box. May/June is still a dream here in Chicago, so planning is my only way to keep sane
Phil

I hear you - we are in the same boat. Let me know when you plan on passing through, we are at the very western end of the canal on the Niagara River. Would be glad to assist you with anything you need.

-ron